The present invention relates generally to distributed sensor network state discovery and maintenance. More specifically, the invention employs a quasi-recursive traversing and interrogating algorithm from a remote location to sensor nodes in a network in order to construct and maintain a relational database model of the sensor network on a database server.
There has been an exponential growth of Internet infrastructure related to electronic data transfer. The expansion was due, in large measure, to what was perceived as a new business model related to the dot.com explosion. The rapid growth of the dot.com world squeezed 30 years of physical plant installation into a five or ten year period. Some say that with the recent implosion of the dot.com world, billions of dollars have been wasted. The Applicants contend that, in fact, this valuable infrastructure, both physical and procedural, offers an enormous opportunity. The new Internet infrastructure can be leveraged and real value can be harvested in support of industry, the consumer sector, users of medical devices, and more. It is precisely this opportunity that is the driving motivation behind the present invention.
Technology development in a number of disparate areas is enabling new interdisciplinary approaches to solve long-standing problems. Three technologies of particular interest are the miniaturization of sensors and actuators, wireless coupling of these devices to enterprise information systems, and software for dynamic, real-time access to remote systems over the Internet. What is needed is a means for converging these technologies, in order to enable the transformation of disconnected sensors generating reams of data into highly connected networks of sensors generating added value information. This convergence will permit organizations to connect all electronic sensing and actuation into a single, integrated information architecture.
The tools needed to implement the vision of seamless, global access to remote information are available only in part, and not yet as an integrated package. The Applicants describe below the development of an information architecture, which is referred to in certain embodiments as Intelemetric(trademark), and a method of using the architecture which make it possible to aggregate, store, process, and distributed, real-time distributed sensor data into the enterprise, and make resulting information readily available over the Internet.
In one aspect, the present invention is an information architecture that permits the Internet to contact distributed sensors at one point, databases and mining engines at another point, and users at another point. In this aspect, the invention is an enabling interface between the Internet and the physical world. Due to the global reach of the Internet, these physical points of contact may be distributed anywhere in the world. The Applicants have invented a sensor network modeling agent for use with a relational database and a logical design resident therein.
In another aspect, the present invention is a method of database modeling that makes it possible to create, store, and update a virtual model of a network of sensors within a relational database structure. The network modeling agent dynamically updates various sensor node data and link data that collectively define an instantaneous xe2x80x9cstatexe2x80x9d of the sensor network into the database logical design. The network modeling agent thereby facilitates access, visualization, and the use of a stream of information generated by the network of distributed sensors. The sensor nodes to be interrogated by the network modeling agent are assumed to be uniquely addressable and in communication, using networking protocols, with one another through links and with a database server through one or more access points. A method according to the present invention comprises the steps of discovering and maintaining the distributed sensor network topology by applying at every access point a uqasi-recursive algorithm, which causes the network modeling agent to visit a first sensor node and mark the first node visited, push the marked first node onto a stack, and while the stack is non-empty, query the node at the top of the stack for a list of current links to the node at the top, compare the list of current links to a list of historical links to the node at the top of the stack and update the historical link and historical node information, and if there are no unmarked nodes reachable from a current link then pop the stack, otherwise visit the next reachable unmarked node, mark the next node and push it onto the stack. The network modeling agent builds the database model by updating relational database logical design tables at each step of the discovering step. The agent maintains the database model by periodically reapplying the interrogating algorithm, thereby updating the database model to account for sensor node and link additions and deletions. The periodicity of updates is preferably such that a near real-time topology of the sensor network is maintained.
In another embodiment, the present invention is a method as described above, wherein the logical design tables further comprise a data table for mapping between one or more sensor nodes and the tables used to store the associated sensor output data associated with the one or more sensor nodes.
In certain embodiments, the present invention is used in modeling networks comprised of mobile sensor nodes. The sensor nodes may communicate by wired or wireless means. The database server used with the present invention may be remotely located from the distributed sensor network.